Vib 170 AL Woofer und Tweeter austauschen?

[YouGo]

Hallo allen,
Bericht aus Holland,

I want to build a Vib 170 Al, but I only like the looks when the tweeter is above the woofer, so I will need to change the design. Will this have influence on the sound?

Danke

[ichse1]

A little bit, but not that important. (edge diffraction)

[derjan]

afaik there's a difference in phase correlation............. when sitting in front of a pair of vib170, your ears are positioned slightly "higher" than the speaker, so the distance between your ear and the tweeter is larger than that one between ear and woofer........

some years ago, visaton had a similar speaker "building suggestion" (bauvorschlag?), technically 99% identical to the vib170, with the tweeter above the woofer, but a slightly "tilted" baffle......... might have the same effect on phase correlation - like placing the woofer above the tweeter.

http://www.visaton.de/vb/showthread....&threadid=7652

afaik, visaton changed the alpha170 to the vib170, because the tilted baffle was for many people too difficult to build, and in order to keep the phase correlation like it had to be, they changed the positions of the drivers.

[YouGo]

Your answer seems technically right, but would I really be able to hear the diffrence or is the design only based on theoretical calculations?

[ichse1]

May be this crossover?

http://www.visaton.cz/czech/clanky/c...bonus_03_2.htm

[YouGo]

Aargh!

The more I read, the more questions I get:
1. Is the diffrence between the original and the upside-down design audible?
2. Is the original crossover better than the one on http://www.visaton.cz/czech/clanky/c...bonus_03_2.htm?
I see the impedance goes from 8 to 6 ohms, the crossover frq goes from 2000 to 2300, the sensivity raises with 1dB and the overall frq response decreases.
3. What is all the czech talking about?

Regards

[ichse1]

1. Is the diffrence between the original and the upside-down design audible?

I don't think so.

[We-Ha]

You build it in original.
Is it ok, then it is good, is it shit, then turn it around (upside down - like australien) and verify it.
Is it ever shit, then burns it and build another Speaker

[monoton]

In two thousand years from now we will have a software for burning our new mediums called VIBs (instead of CDs) that is called YouGo Burning VIB. Only a few will recognize where that came from....

Am I right with my opinion the baffle step problem shouldn't arise at all if he only varies the position of the woofer but keeps the position of the tweeter? Aren't there only the distances between the two sides and the top the critical ones?

monoton

[YouGo]

Hmm that tilted baffle is really ugly.

@Monoton: The diffrence is really in the fact that in the original VIB, the tweeter is furthter away from your ear than te woofer, so you hear the high tones a very little later than the low ones. That may be considered as good.
The distances from the drivers to the edges of the baffle is not really important as far as I know

But because I don't think I can hear the diffrence between the original and the upside-down design, I'll just build my own design, with some changes that I will show you when I'm finished

[monoton]

I think it's the other way around - timecorrect hearing (as you describe it: the sound arriving a TINY little later at the ear) is an approach only very few speaker builder take into consideration, because almost nobody can notice a difference.

But there is an effect on the distances from the drivers to the edges of the baffle, so much, that your crossover should be adapted if you're after the perfect sound. You could build a cheap test-box if you're unsure about the differences between the original and your new setup.

monoton

[derjan]

The reason for modifying the phase correlation between woofer an tweeter (by placing the woofer above the tweeter) is because with an incorrect phase correlation, you have a dip in the frequency response at the crossover frequency. (sounds from woofer an tweeter don't add correctly.......)

I'm also not really sure if s.o. wound ever hear the difference, especially in a normal listening room, where you get much bigger differences in sound by changing the positions of the speakers........

to try and check if there's a noticeable difference, you could build two cabinets using some cheap chipboard oder MDF, and make the upper baffle part changeable / turnable, and maybe mount it with wing nuts.............. (might look like this: http://klamadu.bei.t-online.de/morphy/morphy.htm )

[YouGo]

Okey, I can imagine that the sound changes if a speaker is mounted in a smaller baffle or closer to the edge(s) of a baffle. So in the original design, the woofer is mounted near three edges of the baffle instead of two in my design. Therefor, the air that's moved by the woofer can more easyly flow away. Am I having the point? If I am, I may have a nice solution:

Would this help? In this design, the air moved by the woofer can also more easily flow away, because the baffle is smaller than in the original design

[YouGo]

Does anyone know if this design would compensate the diffrence? You may answer in German, I can read it.

[ichse1]

Not the air flow is the problem, it's the diffraction at the edges.

See this example:




The additional sound coming from the edges is included in the filterdesign. So if you change the dimensions of the baffle, you change the diffracted sound and so the frequency response is not that flat as with the original baffle.

But I don't know if you are able to hear the difference.